The field of the invention generally relates to mailboxes, and more specifically to a mailbox kit having a compact size in its unassembled state compared to its assembled state.
The onset and profound growth of online shopping and associated parcel shipping has driven notable changes in mailbox (also referred to herein as a “mail receptacle”) design. There is growing demand for larger mailboxes that can accommodate larger mail volume and parcel delivery. Concurrently, freight charges incurred throughout the supply chain for bringing products to market have also increased dramatically, with demand often outpacing supply in ocean shipping and with upwardly trending fuel costs. In addition, larger mailboxes require more space during warehouse storage and retail display. As mail and parcel receptacles become larger and freight costs become a larger constituent of overall product cost, methods to reduce the physical volume of a mailbox during shipping, storage and retail display is beneficial.
In response to this growing demand for larger mailboxes, the United States Postal Service (“USPS”) has issued a revision to their USPS Standard 7, from version B to version C. In USPS Standard 7C (Final Rule published in the Federal Register, Volume 80, Number 157), a new size of mailbox is presented, which is much larger than the previous standard and intended to receive most of the common USPS Flat Rate cartons. FIG. 1 shows a comparison of the previous standard mailbox size (the mailbox on the left in FIG. 1), which is still an approved size, and the new larger mailbox (the mailbox on the right in FIG. 1), which is now an additional approved size.
There are some unique constraints that must be considered when designing a mailbox to be sold as an unassembled kit for assembly by the consumer (i.e., a breakdown mailbox). All curbside mailboxes used in the U.S. today must undergo and pass testing against USPS Standard 7, and then be approved by the USPS Engineering Team. Several parts of Standard 7 aim to ensure the final product is large enough for typical deliveries, has the structural rigidity and strength to withstand abusive conditions sometimes experienced during use in the field, and is rainwater tight.
Section 4 of USPS Standard 7 (currently revision C) includes two requirements of particular interest, namely Section 4.8 (Structural Rigidity) and Section 4.9 (Impact Test). USPS Standard 7 identifies the static load and impact locations for these tests, describing how to perform them, and how to evaluate compliance. A paraphrased excerpt from USPS Standard 7 is provided below, with reference to FIG. 2:
1. Strength Test:                a. Apply the load amount shown in the table below at Position #1 onto bolster plate as shown in FIG. 2.        b. Hold for 1 minute.        c. Remove load.        d. Measure permanent deformation. Permanent deformation must not exceed the amount stated in the table.        e. Repeat for positions #2 through #5 using the load amounts shown in the table below.        
PositionMax. Deformation (inches)Load (lbs)1⅛2002⅛2003⅛504⅛505⅛100
2. Impact Test:
a. Drop 10 lb weight onto position #3 from a height of 3 feet using a 2″ x 2″ bolster plate.
b. Observe closely inside and outside for any perforation (hole), crack, sharp edges, and door operation. There must not be any such perforations, cracks, or sharp edges, and the door must still operate normally.
c. Repeat for position #4.
Another section of USPS Standard 7 requires that no water intrude into the mail storage compartment during a specific water tightness test.
Accordingly, there is a need for a compact, mailbox kit which is easy to assemble, has a small unassembled size relative to the size of the assembled mail storage compartment, and meets the USPS standards.